Please don't start out with incorrect statements. It tends to make the rest of your contribution suspect. I've read many of your posts and I have no doubt you know more than me on these engines, so that would be a shame.

The higher the compression, the more spark energy is required to jump the gap and fire the mixture.

Having a mis-matched coil can make the difference between a good running engine and one that misfires badly, especially under load.

.........and this is how threads digress..... sigh.

 

Sorry, but you're wrong about the Pertronix, read the directions- the type of coil used with the Ignitor depends on the rest of the system, voltages, resistors & such, or the module can become toast quickly. Any points-type coil is compatible, but must have the correct input voltages and such. Pertronix's own coil is internally resisted, so if you install it with a primary resistor wire or a ballast resistor, you'll have problems. I just finished fixing a boat that a buddy got a great deal on (22' i/o cabin cruiser for $800!!!). It had a Unilite dizzy in its 302 Ford, the PO had left the key on, and the MSD Blaster II coil had exploded. My bud had bought & installed a new coil, and it wouldn't run above 2500 or make any power- and it blew out one of the exhaust hoses going to the transom when it backfired out the intake and exhaust at the same time behind my shop- he had bought an internal resistor coil, but the system also had a ballast resistor in line. I dug a beat-up old '60's Delco coil out of my junk box and put it on, and all the voltage checks specified for the Unilite came out on the money- he fished all day Sunday in SF Bay with it. Read the Pertronix directions- they know much more about their products than we do.
And if your 10:1 engine wouldn't run with the coil that was on it, you just had a lame coil, and replacing it fixed the problem. C'mon, 10:1? Really? Your average plainjane '60's 390-4V was 10.5:1, most of the other 4V engines about the same, and hundreds of thousands of them ran just fine with stock Autolite coils- in fact the 12:1 427 in my 406 car right now has the original "yellow top" coil off my '69 Mach1 on it, connected to a '65 factory DP dizzy, and goes to 7500+ with no problems. And please- spare me the drama "sigh"
On a lighter note, wanna see an extreme case of coil-overkill? Check out the old Accel Supercoil somebody hung on one of my '47 Indian Chiefs- right below the S&S Super B carb- and yes, it runs that way. That open-fan Hitachi alternator right below yer butt is a nice touch, too

 

LMAO !! Well with the Alt fan sitting there..you wont have to worry about shaving the hair around your **** !! Thats funny as hell..I guess the super coil must be to help hold the front end down on Power shifts ? Love the Scooter tho.. That was back when Bikes were bikes..and Men had to kick start them !

 

Good Morning:

Sorry about that tiny bit of drama I added to my post above. In my experience, having a difference of opinion with a knowlegable and well respected forum member never seems to go well. I unfortunately generalized the problem and put you in that "difficult to deal with" category. I do apologize.

I won't argue anymore, but I'll try to put the facts in a nutshell to explain myself. And I guess it isn't too much of a digression as the OP did ask about using a Pertronix Ignitor

Originally I built up a mild performance FE and used a dual-point distributor and a generic NAPA 12 volt coil with internal ballast resistor. There is no external resistor installed in my car. It ran fine for years.

Trying to get away from points, I thought I'd try a Pertonix Ignitor. I installed it and it worked great. Ran that way for years.

Then I had an incident where I had to have some engine work done which included having the block decks and clylinder heads re-surfaced. Based on what the Machinist told me he took off, I calculated my CR went from 9.5 to 10.

Got everything back together and under hard acceleration, the engine would bog down and misfire very badly. A lot of troubeshooting went on that got me no-where until:

I re-installed the dual point distributor and the problem went away. So I figured the Pertronix Unit went bad. I bought a new one and installed it. Problem came back with new Pertronix Unit.

Having replaced almost everything else in the igntion system, all that was left was the coil. So off I went to NAPA and bought the same coil. Installed new coil and problem was still there with the Pertronix and not there with the points.

I then bought the recommended Pertronix coil and that cured the problem. Has been fine since.

Based on this, I feel comfortable is letting people know that there is the possibility they may need to swith to the recommended Pertronix coil if they are switching from points to an Ignitor unit. It merely ups the cost by about $25 or so.

 

Hey Russ. You must have posted while I was typing. Yes, that motorcycle pic is quite something. Hard to know whether to commend the guy (who did it) for making it all work, or shoot him for *******izing the bike up so badly....LOL.

Edit: Odd what gets censored when I type....

 

LOL...John I feel the same way when I comment sometimes..who toes will I step on..or who will take things the wrong way.. Yeah in all honesty..I think you just got a bad coil..But of course not knowing all the facts you were dealing with at the time..its a hard call.. I do know of some clown that used the longer gap plugs ..and wondered why they wouldnt jump the longer spark..and had to go to a healthier coil to jump the gap..But you were just going on what you knew as the plane facts you delt with..No harm no foul..

Yep that scooters a trip alright ! I agree..woudnt know rather to commend him on his work..or bitch at him for a hack job..But what ever fires your rocket...LOL..I wrote you a rather long Novel thsi morning..You may need to take your morning crap before reading it all..you'll be there awhile...

 

That poor bike has had somewhat of an abused past- and the last registration in '91 says a lot about some of the "detailing". I actually got a pretty good deal on the pair of '47's, as one was a basket and the right tank on this one was whacked- right where the oil tank is. So the guy would fire it up, smoked like a stove, and he thought the engine was shot. I pulled off the back cap on the right tank (fuel half), no gas but 1/2" of oil in the bottom as the bulkhead was ruptured and leaking oil into the gas portion, and both pet***** were open with the lines tee'd into the Super B. I didn't even have to make him an offer, every time his wife looked out and yelled "you'd better sell those things" the price went down So I get 'em home, turn off the right petcock, clean the oil out of the carb & line, hotwire and start kicking- started on the third serious kick, and filled my 42x60 shop with dense smoke, couldn't see the back wall or the cars, had to step outside. Smoke's pouring out the big front doors, and a gal out for her morning run asked if I wanted her to call the fire dept on her cell, please don't, it's OK LOL. Kept getting cleaner and cleaner, set a fan in front of it to keep it cool and ran it for a while, and it never fouled a plug- guess that old engine ain't so bad

 

Cool story, Yeah I have a soft spot for old Indians and Harleys..My Dad had one of each for years..I bought my first Harley at 19 in the service..But it didnt stay around long as it was the AMF years..So I waited til Joe got the company back and then bought one..once he went thru the QC department again.. Sold my FXST when we moved from SoCal to Virginia, have had plans for years to get another one..But just havent..but there will be another before I die come hell or high water ! Dad started me riding when I could kick start his Harley..well that was on the street..had been dirt bikin since 1962..and street riding since 67..had to wear a helmet even before it became law out there, so the cops couldnt see how old I was..Never got busted either..and pulled some really stupid Chit back then.. You gonna keep that as a bobber ? Or restore it back to its original glory ?

 

The ignitor is a nice setup. I have the ignitor III with their coil, and it is very reliable. I did eventually replace the old worn out dizzy for a rebuilt, and it made a big difference. About $50 from Napa, and well worth it. The new dizzy came with the 13L slot. Total timing is 13x2 + 12 initial=38 degrees. Good power and no pinging. By the way, I was able to open the spark plug gap to .045, because of the hotter spark. Good luck.

Kurt